fix: extract shared deleteDirectory utility to eliminate duplication

- Created FileUtils.deleteDirectory() for recursive directory deletion
- GameService.delete() and UploadResource.deleteDir() now delegate to it
- Removed stale BasicFileAttributes import from GameService

src/main/java/com/dostalgia/FileUtils.java

@@ -0,0 +1,28 @@
+package com.dostalgia;
+
+import java.io.IOException;
+import java.nio.file.*;
+import java.nio.file.attribute.BasicFileAttributes;
+
+/** Shared file-system utilities. */
+public final class FileUtils {
+    private FileUtils() {}
+
+    /** Recursively delete a directory tree (walk in reverse order so dirs are empty when deleted). */
+    public static void deleteDirectory(final Path dir) throws IOException {
+        if (!Files.exists(dir)) return;
+        Files.walkFileTree(dir, new SimpleFileVisitor<>() {
+            @Override
+            public FileVisitResult visitFile(final Path f, final BasicFileAttributes a) throws IOException {
+                Files.delete(f);
+                return FileVisitResult.CONTINUE;
+            }
+
+            @Override
+            public FileVisitResult postVisitDirectory(final Path d, final IOException e) throws IOException {
+                Files.delete(d);
+                return FileVisitResult.CONTINUE;
+            }
+        });
+    }
+}

src/main/java/com/dostalgia/GameService.java

@@ -12,13 +12,10 @@ import org.eclipse.microprofile.config.inject.ConfigProperty;
 
 import java.io.IOException;
 import java.io.OutputStream;
-import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
-import java.nio.file.SimpleFileVisitor;
 import java.nio.file.StandardCopyOption;
-import java.nio.file.attribute.BasicFileAttributes;
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Comparator;
@@ -122,21 +119,7 @@ public class GameService implements GameStore {
 
     /** Delete a game and all its files. */
     public void delete(String id) throws IOException {
-        Path dir = gameDir(id);
-        if (Files.exists(dir)) {
-            Files.walkFileTree(dir, new SimpleFileVisitor<>() {
-                @Override
-                public @Nonnull FileVisitResult visitFile(@Nonnull Path f, @Nonnull BasicFileAttributes a) throws IOException {
-                    Files.delete(f);
-                    return FileVisitResult.CONTINUE;
-                }
-                @Override
-                public @Nonnull FileVisitResult postVisitDirectory(@Nonnull Path d, IOException e) throws IOException {
-                    Files.delete(d);
-                    return FileVisitResult.CONTINUE;
-                }
-            });
-        }
+        FileUtils.deleteDirectory(gameDir(id));
         // Clean up old flat .jsdos locations (pre-game-dir layout — backward compat)
         Files.deleteIfExists(gamesDir.resolve(id + ".jsdos"));
         Files.deleteIfExists(gamesDir.resolve(id + ".setup.jsdos"));

src/main/java/com/dostalgia/UploadResource.java

@@ -11,16 +11,12 @@ import org.jboss.resteasy.reactive.RestForm;
 import org.jboss.resteasy.reactive.multipart.FileUpload;
 
 import java.io.IOException;
-import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.SimpleFileVisitor;
 import java.nio.file.StandardCopyOption;
-import java.nio.file.attribute.BasicFileAttributes;
 import java.util.List;
 import java.util.Map;
 import java.util.logging.Logger;
-import jakarta.annotation.Nonnull;
 
 @jakarta.ws.rs.Path("/api/upload")
 @Produces(MediaType.APPLICATION_JSON)
@@ -221,18 +217,6 @@ public class UploadResource {
     }
 
     private void deleteDir(Path dir) throws IOException {
-        if (!Files.exists(dir)) return;
-        Files.walkFileTree(dir, new SimpleFileVisitor<>() {
-            @Override
-            public @Nonnull FileVisitResult visitFile(@Nonnull Path f, @Nonnull BasicFileAttributes a) throws IOException {
-                Files.delete(f);
-                return FileVisitResult.CONTINUE;
-            }
-            @Override
-            public @Nonnull FileVisitResult postVisitDirectory(@Nonnull Path d, IOException e) throws IOException {
-                Files.delete(d);
-                return FileVisitResult.CONTINUE;
-            }
-        });
+        FileUtils.deleteDirectory(dir);
     }
 }